The quality of the Broadway cast is breathtaking. Here's a show that needs open, gregarious touchy-feely performers (if you're in the front few rows, chances are you'll get hugged, kissed, and your hair mussed up - be warned if you're feeling British and reserved) and we loved the different feeling these Americans brought to the old English of the Gielgud theatre.

For all its faults, Hair has some fantastic musical numbers. Galt MacDermot's songs, like Let The Sun Shine In, the Age of Aquarius, I Got Life (which you'll know from the Müller ads) are performed with such classy American polish and panache, both by soloists and the ensemble (and an incredible band), it's a real treat.

In as much as there are lead characters, the two main boys are brilliant. We fell in love with both bad-boy stoner Berger (Will Swenson), and the sexy-but-doomed Claude (Gavin Creel).

But... for all the amazing, boundless energy of the performances, we were still completely lost watching Hair. As a theatre show performed in a slightly sober 2010, it's rambling, formless, and slightly bewildering. Would we have understood it more if we'd gone back to the 60s and been on the same substances as the two East Village stoners, Gerome Ragni and James Rado, who conceived the semi-autobiographical show? Who knows.

Tellingly, one of the most powerful songs in the show isn't by beatniks Ragni and Rado at all: when Claude sings Hamlet's "What a piece of work is man" we finally felt moved, but then Shakespeare does that, doesn't he?

We left the theatre feeling disorientated, confused, claustrophobic, hot, excited and slightly overwhelmed. Possibly like the bad trip that Claude embarks on in the second half. As a play, Hair is all over the place; if you try and go with it, chances are it'll leave you feeling slightly seasick too. But as an exercise in sensory overload, polished performance and a weird trip back in time, this is a really interesting show.